Dental prophylaxis devices

Abstract

The present invention is directed to dental prophylaxis devices that improve portability, maneuverability and aid in retaining clean conditions for use on dental patients, particularly to dental handpieces. The present invention is also directed prophylaxis or prophy angles for use with such handpieces. In general, a dental prophylaxis device includes a handpiece and a prophy angle which includes a driven shaft and a prophy cup attached for rotation thereto. The handpiece generally includes a body which houses a rotational source coupled to an output shaft which couples to the driven shaft in the prophy angle via angled gear interfaces on the output shaft and the driven shaft.

What is claimed is: 
     
       1. A dental prophylaxis device comprising:
 a handpiece having a body; 
 a removable hollow shell surrounding said body; 
 an electric motor mounted inside said body; 
 said electric motor coupled to an output shaft; 
 said output shaft comprising a driving shaft part and an output gear, said output gear having a substantially vertical surface comprising formations on said surface; and 
 a prophy angle removably coupled to said handpiece and said hollow shell and comprising an axial bore having a driven shaft; 
 said driven shaft including a shaft part having two ends, one end ending in a driven gear part and the other end having a prophy cup attached thereon for rotation thereto, said shaft part comprising formations; 
 wherein said electric motor couples to the driven shaft of the prophy angle via the formations on said output gear and the shaft part, said formations on said output gear and the shaft part comprising complementary formations for easy detachment and accurate attachment of the output and driven shafts, and 
 wherein the shell includes a first aperture for inserting the handpiece body into the shell and a second aperture for receiving the output shaft therethrough when the prophy angle is removed from the body, wherein the shell further includes a plurality of circumferentially arranged snap fit arms extending therefrom that include protrusions thereon that are received in a corresponding groove defined in the handpiece, and wherein the snap fit arms extend from the shell into the axial bore of the prophy angle. 
 
     
     
       2. The dental prophylaxis device of  claim 1  wherein said complementary formations comprises the components of at least one of a protrusion and groove or valley connection or a tongue and groove connection. 
     
     
       3. The dental prophylaxis device of  claim 1  wherein:
 said substantially vertical surface further comprises said formations about the periphery of said surface; and 
 said driven gear part is disposed inside said axial bore of said angle, wherein said driven gear part comprises a substantially horizontal surface having formations extending from about the periphery of said substantially horizontal surface; 
 wherein said formations on said substantially vertical surface and said formations on said substantially horizontal surface mate cooperatively during use. 
 
     
     
       4. The dental prophylaxis device of  claim 3  wherein said formations on said substantially vertical surface and said formations on said substantially horizontal surface comprises crown and lantern gears, rack and pinion gears, crown and spur gears, spur to spur gears, crown to crown gears or helical gears. 
     
     
       5. The dental prophylaxis device of  claim 3  wherein said output gear is spring-loaded. 
     
     
       6. The dental prophylaxis device of  claim 3  further comprising a spring for biasing said output gear distally while allowing movement in a proximal direction to provide better mating between the driven shaft and the output shaft during coupling of said shafts. 
     
     
       7. The dental prophylaxis device of  claim 3  wherein said driven shaft is spring-loaded. 
     
     
       8. The dental prophylaxis device of  claim 1  wherein said hollow shell surrounds a portion of the handpiece body and covers a portion of the handpiece for isolating the handpiece from a working space. 
     
     
       9. The dental prophylaxis device of  claim 8  wherein said hollow shell further comprises formations for coupling to the angle. 
     
     
       10. The dental prophylaxis device of  claim 8  wherein said hollow shell is removably coupled to said handpiece body in an anti-rotational manner. 
     
     
       11. The dental prophylaxis device of  claim 1  wherein said body of said handpiece comprises an antimicrobial coating. 
     
     
       12. The dental prophylaxis device of  claim 1  wherein said shell is contoured to said handpiece body for gripping by a user. 
     
     
       13. The dental prophylaxis device of  claim 1  wherein the prophy angle includes a ridge on an inside surface thereof, wherein the shell includes protrusions extending outwardly therefrom, and wherein the ridge on the prophy angle and the protrusions on the shell are in a snap fit relationship.